1 Return Pump, Or 2???

[Forsaken77]

So I've been waiting on the Vectra L1 to be back in stock, but it's taking forever. I have my 180 on hold because of the return pump. It has dual 1" returns.

Would it be better to split the line with a stronger pump, or use 2 smaller pumps for the returns, specifically two of the Reef Octopus VarioS 6 or 8 pumps? I need the head pressure because there's a 25 watt UV on each return and each unit has two 90° angles on top of everything else.

So is 1 pump split better than 2 separate pumps? I know that if one pump goes out the other will still provide flow. That's not my main consideration. It's heat transfer and electricity.

 

[sbash]

Well, two Reef Octopus VarioS 6 uses about the same amount of electricity as the Vectra L1. I am a huge fan of redundancy, so when faced with this question I always choose two. But that might not be the option for everyone.

Splitting the output from the Vectra L1 would increase head pressure, so keep that in mind. Also, 1" return lines seems small for either of these pumps, so that also might create more head pressure.

 

[Rick Krejci]

You would need check valves on both pumps so that if one goes out, the water just wont go back into it since it would likely be that path of least resistance. And check valves are another thing increasing back-pressure and an opportunity for failure.

 

[mcarroll]

So I've been waiting on the Vectra L1 to be back in stock, but it's taking forever. I have my 180 on hold because of the return pump. It has dual 1" returns.

Would it be better to split the line with a stronger pump, or use 2 smaller pumps for the returns, specifically two of the Reef Octopus VarioS 6 or 8 pumps? I need the head pressure because there's a 25 watt UV on each return and each unit has two 90° angles on top of everything else.

So is 1 pump split better than 2 separate pumps? I know that if one pump goes out the other will still provide flow. That's not my main consideration. It's heat transfer and electricity.

Generally one will be better and more efficient.

Consider the flow rate you need to properly support those UV's!!

What organism(s) are you targeting and what is the maximum allowed flow rate for each one to do that?

Are they UV's plumbed for 1" too?

 

[Forsaken77]

Generally one will be better and more efficient.

Consider the flow rate you need to properly support those UV's!!

What organism(s) are you targeting and what is the maximum allowed flow rate for each one to do that?

Are they UV's plumbed for 1" too?

The UV flow rates use a high capacity (I think that's the term) bulb. So I can put 700gph's through each UV to kill algae, bacteria and increase ORP. The UV's come with a hosetail barb (the option I'm using) that goes from 1/2" to 1.25" at the high end of the hosetail. They also come with another 90° output adapter so you can aim the output sideways instead of straight up. So it would be a 90 input, 90 output, plus the 90 adapter (if I needed it).

I was originally going to use a bullhead 1.25" barb T where the input is 1.25" off the pump and the T's are 1" if I split the line.

If I use 2 pumps, the Varios-8 has a 1.25" barb and I would use that straight into 1 UV at that size and have the output be 1" (hosetail barb) exiting the UV into the bulkheads. If I went Varios-6, I'd have to use the 1" barb all the way through. Plus if I use two 6's, I'd probably have to run them at 100%.

But the flow rate is covered for what I want the UV's everyday use to be. The overflows can only do 700gph each, tops. It's just a matter of running one pump or two, and I'd most likely go with the Varios-8's just to have a little leeway.

I was going with the Vectra L1 because of the head pressure it's capable of.

 

[Forsaken77]

You would need check valves on both pumps so that if one goes out, the water just wont go back into it since it would likely be that path of least resistance. And check valves are another thing increasing back-pressure and an opportunity for failure.

I don't use check valves at all. I'm using the Trigger Sapphire 39 (40 gallons) as the sump. According to calculators, it should be able to handle the backflow. Plus if 1 were to fail, it would be a matter of a day before I noticed and it would be removed and replaced.

 

[Forsaken77]

Well, two Reef Octopus VarioS 6 uses about the same amount of electricity as the Vectra L1. I am a huge fan of redundancy, so when faced with this question I always choose two. But that might not be the option for everyone.

Splitting the output from the Vectra L1 would increase head pressure, so keep that in mind. Also, 1" return lines seems small for either of these pumps, so that also might create more head pressure.

Someone else said splitting the lines is the equivalent of using a bigger pipe, reducing head pressure.

The barb the L1 comes with is 1.25", same as VarioS-8. I would use a bullhead T barb where the input would be 1.25" on the barb and the T's would be 1" each. If you buy the L1 barb & screen kit it comes with a 1" barb. That's probably why it has such good head pressure ratings, a few more feet than the VarioS-8

 

[mcarroll]

The UV flow rates use a high capacity (I think that's the term) bulb. So I can put 700gph's through each UV to kill algae, bacteria and increase ORP.

Yes, true, but hte more flow, the less able the treatment....so we have to be specific....or as specific as we can.

So are you literally trying to kill algae, bacteria and raise ORP or are you just going to have it running all the time on General Purpose?

UV without a specific target out of "worry" is expensive and slightly pointless. Even after spending the time and money to keep a big UV system running, you may not even be protecting yourself.

If ich (cilliates) and velvet (armored dino's) are your worries, then do some research or call the vendor and find out the best flow rate for what you're specifically targeting.

If you're just running the system out of fear, these are the two critters I'd target. Hard to kill, so algae and other stuff will be taken care of too. But they will most likely require the lowest flow rates recommended...the highest flow rates will be for bacteria and other very small, simple critters.

Here's some food for thought:

A 180 gallon tank only "needs" at least 360 GPH of return flow. Divide by two and that's only 180 GPH per return outlet.

At most (not considering UV) I'd usually recommend around 720 GPH (4x the display)....that's 360 GPH per return.

It's not likely that either of those flow rates are going to generate much friction in 1" plumbing. Probably not even in 3/4".

Since I have to guess, I'll predict that around 360 GPH will turn out to be just about the right flow rate for those UV's to target heavy-duty critters.

A Quiet One 5000 would do the higher flow rate for only about $100, has a 5 year warranty and has native 1" threaded fittings.

(A Quiet One 4000 would do it for the lower flow rate if that was required for the UV.)

2¢

 

[Forsaken77]

Yes, true, but hte more flow, the less able the treatment....so we have to be specific....or as specific as we can.

So are you literally trying to kill algae, bacteria and raise ORP or are you just going to have it running all the time on General Purpose?

UV without a specific target out of "worry" is expensive and slightly pointless. Even after spending the time and money to keep a big UV system running, you may not even be protecting yourself.

If ich (cilliates) and velvet (armored dino's) are your worries, then do some research or call the vendor and find out the best flow rate for what you're specifically targeting.

If you're just running the system out of fear, these are the two critters I'd target. Hard to kill, so algae and other stuff will be taken care of too. But they will most likely require the lowest flow rates recommended...the highest flow rates will be for bacteria and other very small, simple critters.

Here's some food for thought:

A 180 gallon tank only "needs" at least 360 GPH of return flow. Divide by two and that's only 180 GPH per return outlet.

At most (not considering UV) I'd usually recommend around 720 GPH (4x the display)....that's 360 GPH per return.

It's not likely that either of those flow rates are going to generate much friction in 1" plumbing. Probably not even in 3/4".

Since I have to guess, I'll predict that around 360 GPH will turn out to be just about the right flow rate for those UV's to target heavy-duty critters.

A Quiet One 5000 would do the higher flow rate for only about $100, has a 5 year warranty and has native 1" threaded fittings.

(A Quiet One 4000 would do it for the lower flow rate if that was required for the UV.)

2¢

I'm using it for general purpose. Won't be run 24/7. And if I have an outbreak of something I can dial back the flow. Here's the LINK to where I got it. Just scroll slightly UP to the 25 watt Vecton 600 and it lists the flow rates. Or once at the page you can click the Vecton 600 at the top of the page. The site is full of good info.

It's basically for level 1 sterilization as a general purpose. Takes care of some viruses as well at this level. Being these UV's are connected to the main return pump(s) for the tank, I'm going with a DC pump 100%. It's like a DVR, once you get one you can never go back. Since I've switched to DC return pumps, I can never go back to AC.

Mine are category A UV's
This chart lists gph per watt
So 30-35gph per watt for Level 1

 

[sbash]

Someone else said splitting the lines is the equivalent of using a bigger pipe, reducing head pressure.

I find that unlikely... Increasing the pipe size will decrease friction - base your pipe size of the manufacturers recommendation (it will probably be 1.5 to 2 times the size of the outlet), while adding bends (i.e a Y or T) will increase friction. BUT you are using 1" bulkheads, sot it is fairly moot, lol...

However, if we are dealing with 6 feet of head, ALL of the pumps mentioned should easily be able to handle it; so the head pressure probably should not be a huge factor in your decision...

 

[Forsaken77]

I find that unlikely... Increasing the pipe size will decrease friction - base your pipe size of the manufacturers recommendation (it will probably be 1.5 to 2 times the size of the outlet), while adding bends (i.e a Y or T) will increase friction. BUT you are using 1" bulkheads, sot it is fairly moot, lol...

However, if we are dealing with 6 feet of head, ALL of the pumps mentioned should easily be able to handle it; so the head pressure probably should not be a huge factor in your decision...

With the 90's on both UV's there's a total of 6... 1 in, 1 out, and an optional adapter for sideways direction that I may or may not use. So that's roughly 15ft of combined head pressure.

Thus my dilemma.

This is the Ecotech specs:
Specifications
Flow
Flow: 3,100 gph (11,500 lph)
Max Head Pressure: 21.5 feet (6.5 m)
Input/Output
Input: 1-1/2" (38 mm) QuickCouple
Output: 1" (25 mm) QuickCouple
Power
Wattage: 130 watts

VarioS-8 specs:
Specs:

• Input: 1.25" Male Union Thread
• Output: 32mm/1.25" (barb/pvc coupling)
• Max Flow: 2700 GPH
  
• Max Head: 18 FT
• Wattage: 98W
• Voltage: 36V DC
• Dimensions: 3.75" W x 5.7" L x 5.5" H
  
• Cable Length: 6 FT
• Pump Warranty: 2 Years
• Rotor Warranty: 1 year

 

[Forsaken77]

It's a stock tank with 1" bulkheads both ways. I'm not drilling it myself and am using vinyl tubing on the return.

 

[mcarroll]

I'm using it for general purpose. Won't be run 24/7. And if I have an outbreak of something I can dial back the flow. Here's the LINK to where I got it. Just scroll slightly UP to the 25 watt Vecton 600 and it lists the flow rates. Or once at the page you can click the Vecton 600 at the top of the page. The site is full of good info.

It's basically for level 1 sterilization as a general purpose. Takes care of some viruses as well at this level. Being these UV's are connected to the main return pump(s) for the tank, I'm going with a DC pump 100%. It's like a DVR, once you get one you can never go back. Since I've switched to DC return pumps, I can never go back to AC.

Mine are category A UV's
This chart lists gph per watt
So 30-35gph per watt for Level 1

I think I talked with you or someone else about this brand of UV"s before.....hard to interpret their instructions.

It would appear that you would want target what they refer to as "Level Two Sterilization" to target parasites. But they have subcategories A B and C of which the purpose is not clear. I guess you are an "A".

According to their Flow Calculations, 10-12 GPH is your flow limit for treating "parasites".

• 12 gph/w * 25 watts = 300 GPH
• 300 GPH * 2 Vecton 6's = 600 GPH

If you're in a position to need "parasite-level protection", 600 GPH will do it.

A Recap
2x 180 Gallons = 360 GPH
4x 180 Gallons = 720 GPH

As long as you dial in the correct flow for everyday use – 600 GPH maximum (300 GPH per return) – then all you have to do is turn on the UV and you're burning parasites. No muss, no fuss.

The only mod I'd suggest is to plumb them into a bypass configuration so the flow can be shut off for maintenance (if needed), without shutting off flow to the display.

The only other thing I can think of is that running then continuously (vs keeping them in a closet until needed) entails a little maintenance if they're going to run as you expect. Mulm can build up on the inside, just like with any plumbing. So make sure you get service them easily no matter how you install them.

(If there's any chance of scoring a larger UV filter and trading these in, that would simplify things.....it could be installed before the return splits....half the bulbs, half the maintenance, half the install complexity, etc.)

 

[mcarroll]

Since I've switched to DC return pumps, I can never go back to AC.

The relative warranty (5 vs 2; 3 vs 1) says everything that matters IMO. But that doesn't mean it has to be #1 on your list of concerns.....especially if you already have the DC pump in your possession.

In seriousness, regardless of AC or DC or warranty, I recommend having an identical spare return pump on hand. At last one with identical fittings.

 

[Forsaken77]

The relative warranty (5 vs 2; 3 vs 1) says everything that matters IMO. But that doesn't mean it has to be #1 on your list of concerns.....especially if you already have the DC pump in your possession.

In seriousness, regardless of AC or DC or warranty, I recommend having an identical spare return pump on hand. At last one with identical fittings.

Yeah, I think we discussed the UV's before. But I'm not to concerned with fighting parasites, as have none.

I just wanted to know if it would be better to go with a singular, more powerful pump that's split, of 2 pumps.

Sleepydoc, I believe, said that a split return setup would reduce head pressure because it's the equivalent of a larger diameter pipe.

 

[jeffrey holloway]

I currently run one return pump rated above 3,100 on my 150G . In the past I ran two RO varios 6's on my 150g, one for the 3 reactors and one for RTN and the Chiller. I had great success with this setup. My reasons for going with one pump: I have overkill flow inside my DT with the powerheads I have in there, I got rid of half of the plumbing and created needed space in my sump area, and everyones favorite, "one less pump to clean". I now have two quality backup pumps if ever needed. I Installed flow sensors on my rtn and media reactors so i would know the amount of flow that's really going thru my system. Both setups will work for U. good luck

 

[bif24701]

I know that your returns are 1" but you would reduce friction a lot buy using 1.25 on each line all the way to your 1" bulkheads.

 

[airmotive]

I don't use check valves at all. I'm using the Trigger Sapphire 39 (40 gallons) as the sump. According to calculators, it should be able to handle the backflow. Plus if 1 were to fail, it would be a matter of a day before I noticed and it would be removed and replaced.

You are missing the point.
Centrifugal pumps are non positive displacement. If one pump fails, the majority of the flow from the operating pump will follow the path of least resistance...which is back through the outlet of the failed pump. Hence, the need for check valves on the outlet of each pump. (Or keep the plumbing for each pump completely separate).

 

[Forsaken77]

You are missing the point.
Centrifugal pumps are non positive displacement. If one pump fails, the majority of the flow from the operating pump will follow the path of least resistance...which is back through the outlet of the failed pump. Hence, the need for check valves on the outlet of each pump. (Or keep the plumbing for each pump completely separate).

I got what you were saying, but wouldn't that apply to a syphon system, which this is not? The syphon break holes in the plumbing would prevent this though, right? It's the same as when I hit the feed mode button and the pump shuts off and it drains the water back until it hits the anti-syphon holes in the plumbing.

 

[bif24701]

You could avoid the problem but plumbing each pump with separated systems.